This invention relates in general to material settling devices and, in particular, to a new and useful settling machine and method for upgrading coal or similar minerals, comprising one or more settling chambers filled with water, and including a jig screen for the material to be upgraded, and one or more air chambers which extend laterally of and below the jig screen and the water surface level and which can be pressurized with compressed air in a pulsatory manner, and which are connected to an air tank through air conduits with air inlet connections and air outlet connections and through interposed control valves.